1. Field of the Invention
The present invention relates to a high performance solid catalyst component and an olefin polymerization catalyst using same. More particularly, the present invention relates to a solid catalyst component derived from diethoxymagnesium, titanium tetrachloride and a phthaloyl dichloride in the presence of an alkylbenzene according to a specific procedure and an olefin polymerization catalyst comprising the solid catalyst component, a specific silicon compound and a specific organoaluminum compound, the catalyst being capable of exhibiting an extremely high polymerization activity combined with a high stereospecific performance and producing stereoregular olefin polymers substantially free of any residual chlorine in a high yield.
2. Description of the Prior Art
In recent years, a solid catalyst component comprising magnesium chloride as a support and a titanium compound or the like transition metal compound is widely used for olefin polymerization catalysts. In the use of such solid catalyst component, existence of a halogen contained therein gives a bad influence on the nature of the produced polymer and/or causes corrosion of the apparatus for producing the polymers. In order to eliminate such halogen contained in the polymer, a deashing treatment is additionally needed for the polymerization process, which however, increases the production cost remarkably, thus making the process economically unattractive. Accordingly, the use of such solid catalyst component involves many problems to be solved. To overcome the drawbacks resulting from the use of magnesium chloride, various kinds of solid catalyst components derived from a dialkoxymagnesium, titanium tetrachloride and an electron donor as well as olefin polymerization catalysts comprised of such solid catalyst component have been developed and proposed for the polymerization of olefins. In Japanese Laid open patent appln. No. Sho. 55-152710 and U.S. Pat. No. 4,414,132, for example, there is disclosed the use of a large amount of an organoaluminum compound at the time of polymerization of olefins to enhance activity of such catalysts as well as a process for preparing a catalyst component by bringing a dialkoxymagnesium obtained according to a specific operation into contact with a tetravalent titanium compound in the presence of a halogenated hydrocarbon and an electron donor with the purpose of overcoming drawbacks seen in the prior art processes that stereospecific property of the resultant polymers is deteriorated when hydrogen is added to the polymerization system to control the molecular weight of the produced polymers.
In Japanese Laid-open patent appln. No. Sho. 52-98076, 53-2580, 57-63309 and 61-197607, for example, there is disclosed a process for preparing a solid catalyst component wherein an alkoxymagnesium compound is used in combination with a titanium compound and an electron donor.
However, the solid catalyst components prepared according to the processes illustrated in these prior arts cannot be said to be satisfactory in their catalytic performance. At present, the following five characteristics are required for the solid catalyst components or olefin polymerization catalysts comprised of such solid catalyst components:
(1) High level of polymerization activity PA0 (2) High stereospecific performance PA0 (3) Neither contamination of the produced polymer nor corrosion of the apparatus used for the polymerization PA0 (4) No deterioration of the catalytic activity with the lapse of polymerization time PA0 (5) High bulk specific gravity of the produced polymer. PA0 (A) the solid catalyst component referred to above, PA0 (B) a silicon compound of the general formula: EQU SiR.sub.m (OR').sub.4-m (I) PA0 (C) an organoaluminum compound of the general formula: EQU R".sub.n AlX.sub.3-n (II)
Heretofore, however, there has not et been found any solid catalyst component or olefin polymerization catalyst which succeeds in satisfying all of these five characteristics.
As a result of extensive research, the present inventors already developed an olefin polymerization catalyst which comprises a piperidine derivative, an organoaluminum compound and a solid catalyst which has been prepared by adding a dialkoxymagnesium and a diester of an aromatic dicarboxylic acid to a halogenated hydrocarbon to form a suspension and adding the suspension to a titanium halide to effect reaction (Japanese Laid-open patent appln. No. Sho. 61-108611) and succeeded in furnishing the catalyst with an extremely high polymerization activity and durability of such high activity. However, this catalyst still fails to satisfy all of the above characteristics completely.
Under the above mentioned circumstances, there is still a great demand for developing a new solid catalyst component and a new olefin polymerization catalyst which satisfy all of the above characteristics now required in the industry for the polymerization of olefins.